1. Field of the Invention
The present invention relates to a method of manufacturing an electronic device capable of controlling a threshold voltage, and an ion implanter controller and system that perform the method.
2. Description of the Related Art
Generally, ion implantation for manufacturing an electronic device is performed according to a predetermined ion implantation recipe composed of various ion implantation variables. But the various ion implantation variables are typically fixed regardless of a variation in the critical dimension (CD) of a gate electrode that has already been formed before the ion implantation. However, the variation of the CD of the gate electrode is one of the most critical factors determining the static and/or dynamic performance of an entire electronic device.
According to methods disclosed in the related arts, a gate electrode is formed on a wafer, the CD of the gate electrode is measured, an ion implantation recipe for forming impurity regions, i.e., a lightly doped drain (LDD) region and a source/drain region is adjusted, and ion implantation is performed according to the adjusted ion implantation recipe.
However, such conventional methods only compensate for a variation in the effective length of a channel that occurs due to the variation of the CD of the gate electrode. Yet, the variation of the CD of the gate electrode causes a threshold voltage as well as the effective length of the channel to vary. Therefore, it is impossible to sufficiently compensate for threshold voltage variations caused by the variation of the CD of the gate electrode by simply adjusting the ion implantation recipe, which only affects the effective length of the channel. Accordingly, it is still impossible to prevent static and/or dynamic refresh failures caused by the variation of the CD of the gate electrode from occurring.